2X NB with appropriate selection. Cultures for minimal inhibitory concentration (MIC) determination were diluted 1:1000 in 3 ml of 0.1X NB for chromate cultures or mXBM plus glucose for divalent cationic metals in borosilicate glass tubes and maintained at 30°C with shaking at 200 rpm. The OD600 was measured daily for a period of 3 days until growth stabilized. Divalent cationic metals used in MIC experiments were added as
lead nitrate (Pb(NO3)2, zinc chloride (ZnCl2), or cadmium sulfate (CdSO4) at concentrations ranging from 0 to 200 μM. Cultures were prepared in triplicate for each MK-0457 solubility dmso growth or MIC experiment. D11 transformants were screened for chromate resistance by streaking single colonies onto 0.1X nutrient agar plates containing 0, 0.5, 1, 2, or 5 mM chromate. Sequence analysis of putative chromate efflux gene The genome sequence is available in the GenBank database under accession numbers NC_008537 to NC_008539 and NC_008541. The genome was sequenced by the Department of Energy Joint Genome Initiative INCB28060 supplier (DOE-JGI) and can
be accessed at http://genome.jgi-psf.org/finished_microbes/art_f/art_f.home.html.
The annotated sequence at this site was used for locating the CRD and construction of primer sequences. Thymidylate synthase Multiple sequence alignment of Arth_4248 (ChrA) with other described and putative members of the CHR family of chromate efflux proteins [24] was performed using the ClustalX program and P505-15 in vitro default setting for Gonnet series for protein weight matrix [51] and bootstrap Neighbor Joining tree options with 1000 resamplings. Output trees were visualized in Fig Tree http://tree.bio.ed.ac.uk/software/figtree/. Sequences were retrieved from the UniProt database [52] by conducting a search for ChrA sequences according to Diaz-Perez et al [22]. Some additional eukaryotic sequences were found by conducting a similar search of the GenBank database [53]. All short ChrA (SCHR) sequences (<350 amino acids) were excluded from the alignment. A total of 513 sequences (Additional files 1 and 2) were retrieved and aligned. Transmembrane helices were predicted using the TMHMM 2.0 server [54].